mga_vid and interlaced output via DVI (NOT tv-out)

hi all,

since many years i had my self made htpc running with a g400 and tvout via 
rgb.

now i moved to a g550 and have a pioneer plasma connected with a dvi to hdmi 
cable. i had to create some fb.mode entries but and it works fine in all 
progressive modes (576p, 720p, 1080p). but from my point of view the pioneers 
builtin deinterlacer is much better than any of mplayers deinterlacers.

so i tried to use 576i. after i realized that the horizontal resolution has 
to be doubled from 720 to 1440, i got a framebuffer console working. mplayer 
with -vo fbdev also works in the way one can expect from this mode.

with mga_vid my problem is that all lines are doubled. i see a stretched 
picture consisting of the first 288 lines of the picture with correct width. 
i tried this with test_mga_vid, same result: the test pattern are not square, 
they have double height while the framebuffer console in the background is 
ok.

for me this looks like some layer expects even and odd frames to be provided 
one after the other, each with 288 lines instead of interleaved with 576 
lines.

now the question: how can i fix this? is there any bes register witch has to 
be set in a different way?

btw: when trying 1080i i have exectly the same problem.


thanks for any idea,

michael